Publication

New ATLAS publication

Measurement of the tttt production cross section in pp collisions at sqrt(s)=13 TeV with the ATLAS detector ” has been submitted to JHEP. Members of the IFAE-ATLAS team (Aurelio Juste, Nicola Orlando, and Anil Sonay) have played a leading role in this publication, from designing the analysis strategy to the final multivariate technique and statistical analysis employed.

This paper presents a measurement of the four-top-quark production cross section in final states with a single lepton or an opposite-sign lepton pair in association with multiple jets using the full Run 2 dataset collected with the ATLAS detector. With four top quarks produced per event, this is a very rare Standard Model process with a predicted cross section of only 12 fb, and thus is very sensitive to beyond-the-SM (BSM) contributions. A sophisticated event categorization and multivariate technique is used to discriminate signal from background events. The result of this analysis is combined with a previous measurement in multilepton final states. The combined cross section is measured to be a factor of two higher than the SM prediction, although compatible with it within 2.0 standard deviations. The corresponding observed (expected) signal significance is .7 (2.6) standard deviations over the background-only prediction.

The IFAE team is currently working on an improved analysis targeting BSM production of four-top-quark events. Stay tuned!

More information on the ATLAS Physics Briefing

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Latest Group News

New Member

New Member in the ATLAS group

September 7, 2022

Gabriel Corrêa has just joined the ATLAS group as a PhD student.

Instrumentation

The ALTIROC2 device assembled at IFAE tested for the first time with a particle beam

July 27, 2022

An ALTIROC2 device assembled at IFAE was tested for the first time with a particle beam

New results

New ATLAS results for ICHEP 2022

July 13, 2022

Members of the IFAE-ATLAS team have played a leading role in two of the 31 new results released by ATLAS at ICHEP 2022. The corresponding publications will be submitted to the journal soon.